/*
 * C99-compatible snprintf() and vsnprintf() implementations
 * Copyright (c) 2012 Ronald S. Bultje <rsbultje@gmail.com>
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <stdio.h>
#include <stdarg.h>
#include <limits.h>
#include <string.h>

#include "compat/va_copy.h"
#include "libavutil/error.h"

#if defined(__MINGW32__)
#define EOVERFLOW EFBIG
#endif

int avpriv_snprintf( char *s, size_t n, const char *fmt, ... )
{
    va_list ap;
    int ret;

    va_start( ap, fmt );
    ret = avpriv_vsnprintf( s, n, fmt, ap );
    va_end( ap );

    return ret;
}

int avpriv_vsnprintf( char *s, size_t n, const char *fmt,
                      va_list ap )
{
    int ret;
    va_list ap_copy;

    if ( n == 0 )
        return _vscprintf( fmt, ap );
    else if ( n > INT_MAX )
        return AVERROR( EOVERFLOW );

    /* we use n - 1 here because if the buffer is not big enough, the MS
     * runtime libraries don't add a terminating zero at the end. MSDN
     * recommends to provide _snprintf/_vsnprintf() a buffer size that
     * is one less than the actual buffer, and zero it before calling
     * _snprintf/_vsnprintf() to workaround this problem.
     * See http://msdn.microsoft.com/en-us/library/1kt27hek(v=vs.80).aspx */
    memset( s, 0, n );
    va_copy( ap_copy, ap );
    ret = _vsnprintf( s, n - 1, fmt, ap_copy );
    va_end( ap_copy );

    if ( ret == -1 )
        ret = _vscprintf( fmt, ap );

    return ret;
}
